Regulators are used to stabilize a power supply voltage to be supplied to a sensor element or a signal processing circuit and to cope with a drop of a circuit operation voltage that accompanies miniaturization of a process. Although the regulator absorbs voltage fluctuation of the power supply line and supplies a stabilized predetermined voltage to the sensor element or the signal processing circuit, when the negative surge is impressed to the power supply line, there may be a case where a current flows back in a transistor for driving a load of the regulator, and the output voltage of the regulator drops. Thereby, load circuits, such as the sensor element and the signal processing circuit, may be reset, and malfunctions, such as outputting an abnormal value and a reboot operation, may occur. In order to suppress such a malfunction, it is necessary to make the current not flow back at the time of negative surge impression. A technology described in PTL 1 includes a diode between a power supply line and a collector terminal of an NPN bipolar transistor for load driving (hereinafter referred to as NPN transistor). Since this diode prevents a reverse current that flows from the load side to the power supply line at the time of the negative surge impression, the malfunctions described above can be suppressed.